Statistics

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Category archives for Statistics

Going for a Sweep in Game 3

Dak at Fire Joe Morgan asks: I’ve been watching a fair amount of SportsCenter / BBTN today, and every two minutes someone mentions that there are “seven teams going for a sweep in an interleague series!”, as if this is some sort of big deal. There are fourteen interleague series this weekend. If every match…

On Tuesday night, the National Basketball Association (NBA) held their annual draft lottery. In the draft, each team is given the opportunity to select a few players that have declared themselves eligible for the draft (either after completing at least one year of college in the United States or being from another country and over…

Mark Liberman has an excellent post examining the general public’s understanding of basic statistical concepts such as means, variances, and distributions. Here’s a taste: Until about a hundred years ago, our language and culture lacked the words and ideas needed to deal with the evaluation and comparison of sampled properties of groups. Even today, only…

Flipping Alleles

For some reason, John Hawks thinks my disc flipping calculations have something to do with population genetics. He extends it to FST, which is just plain ridiculous. There is nothing about binomial sampling that can be related to popgen theory. Nothing.

Usually Choose Same

In yesterday’s post, I argued that, when flipping two unfair discs (or coins), there is a greater chance that both discs will land with the same side up than different sides up. As pointed out in the comments, I was assuming that the probability of heads is equal for both discs: Aren’t you assuming that…

Always Choose “Same”

The beginning of many Ultimate (nee, Frisbee) games is marked by flipping discs to decide which team must pull (kick off) and which goal each team will defend at the start of the game. This is sort of like the coin flip before an American Football game. Two players — one from each team —…

Math for Biologists

Keith Robison, at Omics! Omics!, asks and answers the question, “What math courses should a biologist take in college?” His answer: a good statistics course is a must (one where you learn about experimental design and Bayesian statistics), and a survey course that covers topics like graph theory and matrix math would provide a nice…

Redefining the Binomial

There’s an interesting post over at Statistical Modeling, Causal Inference, and Social Science on calculating probabilities. Traditionally, if you observe a certain number of events (y) in some number of trials (n), you would estimate the probability (p) of the event as y/n. To calculate the variance around this estimate, you would use this equation:…

I Got Your Distribution Right Here

In the comments of my dinosaur genome size post, Shelley asked: So do ALL birds have equally small genomes or is there variation among species? I don’t think she was looking for a trite response along the lines of: “Of course there’s variation among species.” What she was asking, I presume, is how much variation…

Mining for Statistical Significance

The curtain has been drawn and the secrets to data analysis revealed. Do you have a data set sitting around in need of analysis? Read this and learn how to find significant results somewhere — anywhere — in your data. Because negative results won’t get you published; and you won’t get hired/tenure if you don’t…